Neither consideration nor measures especially for reflection of a sound is usually taken in a room space of a room of a standard building or house. When a musical instrument player makes a practice of a musical performance or an inhabitant listens to music in such a room space, a peculiar reflection of sound may occur in the room space, and a reflected sound and a sound actually outputted from a musical instrument or acoustic equipment may come into ears of a human in a mixed state with each other.
As a result, a person in the room may often fail to listen to the original sound to be caused to listen to. There have conventionally been contrived various ways to improve such a situation to solve dissatisfaction with the sound.
There has conventionally been taken a way, as the most usual countermeasure to such a useless reflection of sound, of providing an object having a function of absorbing the sound without reflecting it on a ceiling or in front of a wall of the room, to cause it to absorb a part or whole of the sound generated from a sound source such as a music instrument, in order to inhibit an occurrence of a peculiar reflection of sound in the room space of a small room, thus inhibiting the useless reflection of sound.
An example of the sound absorber, which has conventionally been used for absorption of sound, is disclosed in JP 10-254452 A, JP 11-3082 A, JP 2001-207366 A, JP 2006-30905 A and JP 2009-287143 A.